A laundry dryer is an electronic appliance that can dry wet laundry by supplying a high temperature and dry hot wind into a drum in which the wet laundry is stored.
There is an increasing demand for such laundry dryers.
That is, the laundry dryer is designed to dry the laundry using the hot wind while lifting and dropping the laundry loaded in a drum rotating by a driving motor. The laundry dryer may be classified into an exhaust-type dryer and a condenser-type dryer. The former is designed such that high-temperature and humidity air absorbing moisture from the laundry in the drum is exhausted out of the dryer. The latter is designed such that the air circulating in the dryer absorbs the moisture from the laundry loaded in the drum.
In addition, the laundry dryer includes a dry drum in which the wet laundry is loaded and a heater and blower fan for supplying hot wind into the dry drum. A lift is mounted on an inner circumference of the dry drum to lift the laundry loaded in the drum when the dry drum rotates at a high speed. The laundry drum is provided at a front surface with an opening through which the laundry is loaded therein. An inner circumference defining the opening is supported by a front cover defining the front surface of the laundry dryer. The dry drum may be designed such that a rear surface thereof may integrally rotate together with a cylindrical main body of the dry drum. Alternatively, the dry drum may be designed such that the rear surface thereof may be fixed on a back cover so that only the cylindrical main body of the dry drum can rotate alone.
When the dry drum is designed such that the rear surface thereof rotates together with the cylindrical main body of the dry drum, the dry drum is formed by rolling up a single metal plate into a cylindrical shape and welding the metal plate. The front opening of the dry drum is supported on a rear surface of the front cover and the rear surface of the dry drum is supported on a back cover by a journal bearing.
When the dry drum is formed of the single metal plate, there is a problem in that the thickness of the metal plate should be increased to endure the load of the drum at both ends.
In addition, a coupling member is inserted penetrating the dry drum to couple the lift on the inner circumference of the dry drum. At this point, since an outer end of the coupling member is projected from the outer circumference of the dry drum, the projected outer end may interfere with a belt wound around the outer circumference of the dry drum. That is, by the projected outer end, the belt may be damaged or torn up.
In addition, a penetration hole is formed on the dry drum so that the coupling member penetrates therethrough. In this case, by burrs generated during the penetration hole forming process, the coupling member may be easily inserted into the fenestration hole.
Furthermore, the main body of the dry drum is formed by rolling up a rectangular plate and welding opposite ends of the plate. At this point, the welding portion may be projected from the outer circumference of the drum, conflicting with the belt.